To create such a light pulse, the team, led by LOA, created a superefficient light source that could deliver 1000 identical femtosecond (10-15 seconds) long pulses per second. The researchers focused the 1-μm-wide beam on a silicon target. The intensity of the beam turned the solid silica into plasma of the same density. The laser excited the electrons within the plasma, causing them to emit EUV radiation that can be recorded.